Golf club head

ABSTRACT

This golf club head includes a face portion, a crown portion and a sole portion, the crown portion including a first region extending along at least part of the face portion, a second region arranged further on a back side than the first region, and a step region extending in the toe-heel direction between the first and the second regions and extending downward toward the second region from the first region side, the first region being formed to at least extend from a position Ph that is 20 mm on a heel side to a position Pt that is 25 mm on a toe side, based on a face center, and a width Dh of the first region in a face-back direction at the position Ph and a width Dt of the first region in the face-back direction at the position Pt satisfying 1&lt;(Dt/Dh)≤1.35.

TECHNICAL FIELD

The present invention relates to a golf club head.

BACKGROUND ART

In recent years, golf club heads have been proposed in which a raisedportion extending in the toe-heel direction is provided on the crownportion and a sloped surface is formed as a step between the raisedportion and the portion rearward thereof (e.g., JP 2015-29628A). Agolfer, by sighting this step, is better able to determine the directionof the shot at address.

JP 2015-29628A is an example of related art.

SUMMARY OF THE INVENTION

Incidentally, golfers, in order to better catch the ball or to preventslicing, sometimes intentionally grip the club at address with the facerotated in a direction that closes the face (e.g., in a directionwhereby the face is turned to the left of the target direction in thecase of a right-handed club). Note that “better catching the ball”refers, for example, to ensuring that the ball is not launched to theright of the intended launch direction (left-right direction), in thecase of a right-handed golfer. However, golfers normally address theball such that the orientation of the face (e.g., orientation of theupper end edge of the face in the case of a wood-type golf club) isperpendicular to a target line (target direction) as a reference ataddress. Thus, in the case where the face is closed at address asdescribed above, the orientation of the face is not perpendicular to thetarget direction, possibly giving rise to a sense of incongruity.

In particular, with a club such as described in JP 2015-29628A, there isa problem in that since a step is formed on the crown portion, theorientation of the face becomes easier to sight, thereby exacerbatingthe sense of incongruity. The present disclosure was made in order tosolve this problem, and an object thereof is to provide a golf club headthat is able to reduce the sense of incongruity even when the face isclosed at address.

A golf club head according to the invention includes a face portion, acrown portion and a sole portion, the crown portion including a firstregion extending in a toe-heel direction along at least part of the faceportion, a second region arranged further on a back side than the firstregion, and a step region extending in the toe-heel direction betweenthe first region and the second region and extending downward toward thesecond region from the first region side, the first region being formedto at least extend from a position Ph that is 20 mm on a heel side to aposition Pt that is 25 mm on a toe side based on a face center, and awidth Dh of the first region in a face-back direction at the position Phand a width Dt of the first region in the face-back direction at theposition Pt satisfying 1<(Dt/Dh)≤1.35.

In the above golf club head, a difference between the width Dh and thewidth Dt can be set to 6 mm or less.

In the above golf club heads, a length of the first region in theface-back direction can be set to 5 to 30 mm, between the position Phand the position Pt.

In the above golf club heads, an angle θ formed by a straight lineconnecting the position Ph and the position Pt at an end edge on a faceside of the first region and a straight line connecting the position Phand the position Pt at the end edge on a back side of the first regioncan be configured to satisfy 0 degrees<θ≤8 degrees.

In the above golf club heads, a face angle FA of the face portion can beconfigured to satisfy −5 degrees≤FA≤0 degrees.

With a golf club head according to the present invention, the sense ofincongruity can be reduced even when the face is closed at address.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a golf club head according to thepresent embodiment as seen from the face side.

FIG. 2 is a perspective view of the golf club head in FIG. 1 as seenfrom the back side.

FIG. 3 is a plan view of a reference state of the head in FIG. 1.

FIG. 4 is a cross-sectional view along an A-A line in FIG. 3.

FIG. 5A is a diagram illustrating the boundary of a face portion.

FIG. 5B is a diagram illustrating the boundary of the face portion.

FIG. 6 is a plan view showing the head at address.

FIGS. 7A to 7C are plan views showing other examples of the raisedportion.

EMBODIMENTS OF THE INVENTION

Hereinafter, an embodiment of a golf club head according to the presentinvention will be described, with reference to the drawings. FIG. 1 is aperspective view of this golf club head as seen from the face side, FIG.2 is a perspective view of this golf club head as seen from the backside, FIG. 3 is a plan view of the head in a reference state, and FIG. 4is a cross-sectional view along an A-A line in FIG. 3. Note that thereference state of the golf club head will be discussed later.

1. Overview of Golf Club Head

As shown in FIGS. 1 to 4, this golf club head (hereinafter, may besimply referred to as “head”) 100 is a wood-type golf club head having ahollow structure with an internal space, and a wall surface is formed bya face portion 1, a crown portion 2, a sole portion 3 and a hoselportion 4. Specifically, the present invention is applicable to golfclub heads such as utilities, fairway woods and drivers.

The face portion 1 has a face surface which is the surface that hits theball, and the crown portion 2 adjoins the face portion 1 and constitutesthe upper surface of the head 100. The sole portion 3 mainly constitutesthe bottom surface of the head 100, and constitutes the outer peripheralsurface of the head 100 other than the face portion 1 and the crownportion 2. That is, besides the bottom surface of the head 100, theregion extending from the toe side of the face portion 1 around the backside of the head to the heel side of the face portion 1 is also part ofthe sole portion 3. Furthermore, the hosel portion 4 is a region that isprovided adjoining the heel side of the crown portion 2, and has aninsertion hole 41 into which the shaft (illustration omitted) of thegolf club is inserted. A center axis line Z of this insertion hole 41coincides with the axis line of the shaft.

Here, the reference state when setting the golf club head 100 on theground will be described. First, as shown in FIGS. 3 and 4, a statewhere the above center axis line Z is contained in a plane P1 that isperpendicular to the ground and the head is placed on the ground at apredetermined lie angle and real loft angle is prescribed as thereference state. The above plane P1 will be referred to as the referenceperpendicular plane. Also, as shown in FIG. 3, the line of intersectionbetween the above reference perpendicular plane P1 and the ground willbe referred to as the toe-heel direction, and the directionperpendicular to this toe-heel direction and parallel to the ground willbe referred to as the face-back direction. Also, the direction that isorthogonal to the toe-heel direction and the face-back direction may bereferred to as the up-down direction.

In the present embodiment, the boundary between the face portion 1 andthe crown portion 2 and between the face portion 1 and the sole portion3 can be defined as follows. That is, in the case where a ridgeline isformed therebetween, this ridgeline will be the boundary. On the otherhand, in the case where a clear ridgeline is not formed, in each ofcross-sections E1, E2, E3 and so forth that contain a straight line Nconnecting a head center of gravity G and a sweet spot SS, as shown inFIG. 5A, a position Pe at which a curvature radius r of a contour lineLf of the face outer surface first reaches 200 mm in a direction towardthe face outer side from the sweet spot side, as shown in FIG. 5B, willbe the periphery of the face portion 1, and this periphery is defined asthe boundary with the crown portion 2 or the sole portion 3. Note thatthe sweet spot SS is the point of intersection between the normal(straight line N) of the face surface that passes through the headcenter of gravity G and this face surface.

Also, in the present embodiment, the boundary between the crown portion2 and the sole portion 3 can be defined as follows. That is, in the casewhere a ridgeline is formed between the crown portion 2 and the soleportion 3, this ridgeline will be the boundary. On the other hand, inthe case where a clear ridgeline is not formed therebetween, the contourwhen the head is set in the reference state and viewed from directlyabove the center of gravity of the head 100 will be the boundary.

Also, the head 100 can, for example, be formed with a titanium alloy(Ti-6Al-4V) having a specific gravity of substantially about 4.4 to 4.5.Also, apart from a titanium alloy, the head can also be formed using oneor two or more materials selected from stainless steel, maraging steel,an aluminum alloy, a magnesium alloy and an amorphous alloy, forexample.

Also, the volume of this golf club head 100 is from 80 cm³ to 460 cm³inclusive, for example.

2. Assembly Structure of Golf Club Head

The golf club head 100 according to the present embodiment isconstituted, as shown in FIG. 4, by assembling a head main body 101having a crown portion 2 and a sole portion 3 and a cup-shaped facemember 102 having a face portion 1 and a peripheral portion 15 extendingfrom the periphery of the face portion. This head main body 101 has anopening 18 enclosed by the crown portion 2 and the sole portion 3, andthe face member 102 is attached so as to close off this opening 18. Thatis, an end face of the peripheral portion 15 of the face member 102 isbutted against an end face of the opening 18 of the head main body 101,and these portions are joined by welding (so-called cup face structure).The face member 102 is integrated with the head main body 101, by beingattached to an edge portion of the opening 18 of the head main body 101,and the peripheral portion 15 of the face member 102 thereby functionsas part of the crown portion 2 and the sole portion 3 of the head 100.

Accordingly, the surface that is integrally formed as a result of theperipheral portion 15 of the face member 102 being attached to the headmain body 101 constitutes the crown portion 2 and the sole portion 3 ofthe head 100. Thus, strictly speaking, the crown portion 2 and the soleportion 3 of the head main body 101 are part of the crown portion 2 andthe sole portion 3 of the head 100, although, in this specification,these portions of the head main body 101 may also be referred to simplyas the crown portion 2 and the sole portion 3, without making thisdistinction.

3. Structure of Crown Portion

Next, the crown portion 2 will be described. As shown in FIGS. 1 to 4,the crown portion 2 is constituted by a raised portion (first region) 21that is arranged on the face portion side and a base portion (secondregion) 22 that is arranged further on the back side than the raisedportion 21. The raised portion 21 is mainly a band-like region extendingin the toe-heel direction along the face portion 1, with the respectiveend portions on the toe and heel sides extending slightly to the backside along the periphery of the crown portion 2, and is formed as awhole to be U-shaped in plan view. Accordingly, the end edge on the backside of the raised portion 21 is slightly curved. On the other hand, thebase portion 22 is a region that occupies most of the crown portion 2 ata lower position than the raised portion 21, and the periphery thereofcontacts the sole portion 3. A sloped surface (step region) 23 thatconstitutes a step is formed on the boundary between the raised portion21 and the base portion 22. The height of the face portion 1 in theup-down direction is thereby increased by the amount of the step betweenthe raised portion 21 and the base portion 22.

This sloped surface 23 is configured so as to extend upward, movingtoward the face portion 1 side. The sloped surface 23 can thereby besighted from above, when the golf club head 100 is set in the referencestate. That is, the sloped surface can be sighted by the golfer ataddress. The sloped surface 23 is formed along the raised portion 21,and is thus formed to be U-shaped in plan view, similarly to the raisedportion 21.

As shown in FIG. 3, a width D of the raised portion 21 in the face-backdirection can be prescribed as follows. That is, a position Pt that is25 mm on the toe side and a position Ph that is 20 mm on the heel sidefrom the face center C are prescribed. The raised portion 21 is formedsuch that Dt and Dh satisfy the following in equation (1), where Dt isthe width of the raised portion at the position Pt and Dh is the widthof the raised portion 21 at the position Ph.

1<(Dt/Dh)≤1.35  (1)

Note that (Dt/Dh) is preferably 1.3 or less, and more preferably 1.25 orless. Also, (Dt/Dh) is preferably 1.05 or more, and more preferably 1.1or more.

That is, the raised portion 21 is formed such that Dt is greater thanDh. Specifically, the lengths of Dt and Dh are, for example, preferablyset such as shown in the following in equations (2) and (3).

10 mm≤Dt≤30 mm  (2)

6.5 mm≤Dh≤30 mm  (3)

Within the range from the position Pt to the position Ph, the width D ofthe raised portion 21 preferably satisfies the following in equation(4).

5 mm≤D≤30 mm  (4)

Also, a difference Dn between Dt and Dh is preferably set as follows.

Dn≤6 mm  (5)

Note that Dn is more preferably set to 5 mm or less, and is particularlypreferably set to 4 mm or less.

Also, a straight line L1 connecting an end edge Pt1 on the face side ofthe raised portion 21 at the position Pt and an end edge Ph1 on the faceside of the raised portion 21 at the position Ph is prescribed.Furthermore, a straight line L2 connecting an end edge Pt2 on the backside of the raised portion 21 at the position Pt and an end edge Ph2 onthe back side of the raised portion 21 at the position Ph is prescribed.In this case, an angle θ formed by the straight line L1 and the straightline L2 preferably satisfies the following in equation (6).

0<θ≤8 degrees  (6)

Note that the face center can be defined as follows.

First, an arbitrary point Po is determined generally in a vicinity ofthe middle of the face portion 1 (face surface) in the toe-heeldirection and the up-down direction. A line x extending in the toe-heeldirection is drawn through this point Po, and a midpoint Px of this linex is determined. Next, on the face portion 1, a line y extending in theup-down direction is drawn through the point Px, and a midpoint Py ofthis line is determined. A process of redrawing the line extending inthe toe-heel direction through the point Py determined in this way asthe line x and thereafter redetermining the point Py in a similar mannerto that described above is then repeatedly performed. A new point Py atwhich the distance between the previous point Py and the new point Pybecomes 0.5 mm or less during the repetitions of this process is definedas the face center. Note that, more specifically, the above line xpassing through the point Po is the line of intersection between theface surface (surface of the face portion 1) and a plane that containsthe normal of the face surface passing through this point Po and isparallel to the toe-heel direction. Also, more specifically, the aboveline y passing through the point Px is the line of intersection betweenthe face surface and a plane that contains the normal of the facesurface passing through this point Px and is parallel to the up-downdirection. Also, more specifically, the above line x passing through thepoint Py is the line of intersection between the face surface and aplane that contains the normal of the face surface passing through thispoint Py and is parallel to the toe-heel direction. Note that thelengths of the above lines x and y are measured along the face surface.

Also, as shown in FIG. 4, a width W of the sloped surface 23 in theface-back direction in plan view is preferably set from 3 to 9 mm, andmore preferably from 3 to 7 mm, for example. Furthermore, a height H ofthe sloped surface 23 is preferably set from 0.5 to 8 mm, morepreferably from 0.5 to 6 mm, and particularly preferably from 0.5 to 5mm, for example.

4. Structure of Face Portion and Sole Portion

The structure of the face portion 1 and the sole portion 3 is notparticularly limited. With regard to the face portion 1, the thicknessthereof can be appropriately changed, for example. Also, a face angle FApreferably satisfies the following in equation (7).

−5 degrees≤FA≤0 degrees  (7)

Note that the face angle FA is defined as follows. First, a straightline FL connecting two points F1 and F2 on the face surface at positionsrespectively spaced by 40 mm on the toe side and the heel side of theface center is drawn with the head in the reference state. The angleformed by this straight line FL and a straight line extending parallelto the toe-heel direction is defined as the face angle FA. Note that inthe case where the points F1 and F2 cannot be taken on the face surfaceof the head due to the size of the face surface, a straight lineconnecting two points on the face surface at positions respectivelyspaced by 30 mm on the toe side and the heel side of the face center isdetermined as the straight line FL. Also, the sign of the face angle FAis positive in the case where the face is turned in a direction thatcloses the face (discussed above), and is negative in the case where theface is turned in a direction that opens the face (e.g., in a directionwhereby the face is turned to the right of the target direction, in thecase of a right-handed club).

Also, with regard to the structure of the sole portion 3, recesses andprotrusions can be appropriately formed and the thickness can be changedfrom a design or performance viewpoint.

5. Manufacturing Method of Golf Club Head

Next, an example of the manufacturing method of the above golf club headwill be described. First, the abovementioned head main body 101 and facemember 102 are prepared. A head main body 101 and a face member 102 suchas described above can be produced with various methods. For example,the head main body 101 can be manufactured by casting such as awell-known lost wax precision casting process. Also, the face member 102can be manufactured by a method such as forging, plate pressing orcasting, for example.

The golf club head is then completed when predetermined coating isperformed after joining these portions by welding (TIG (tungsten inertgas) welding, plasma welding, laser welding, brazing, etc.), forexample.

6. Features

According to the above embodiment, the following effects can beobtained.

(1) In the crown portion 2, the raised portion 21 is formed higher thanthe base portion 22 via the sloped surface 23, thus enabling the heightof the face portion 1 to be increased by the height of the raisedportion 21. Thus, the rebound performance of the face portion 1 can beimproved. Also, in the crown portion 2, only the raised portion 21 isformed higher, and the base portion 22 occupying most of the crownportion 2 is formed at a lower position than the raised portion 21, thusenabling the center of gravity of the head to be lowered.

(2) At address, the orientation of the head can be determined utilizingthe end edge on the back side of the raised portion 21. At this time,since the widths Dt and Dh of the raised portion 21 satisfy in equation(1), the end edge on the back side of the raised portion 21 extends suchthat the distance between the end edges of the raised portion 21 on theback and face sides is greater at the position Pt on the toe side thanat the position Ph on the heel side. Thus, the following effects can beobtained.

Golfers, in order to better catch the ball or to prevent slicing,sometimes intentionally grip the club at address with the face rotatedin a direction that closes the face (e.g., in a direction whereby theface is turned to the left of the target direction, in the case of aright-handed club). At this time, the upper end edge of the face surface(end edge on the face side of the raised portion 21) slopes relative tothe target line rather than being orthogonal thereto, whereas the endedge on the back side of the raised portion 21, due to satisfying theabove in equation (1), extends in a direction orthogonal to the targetline. That is, as shown in FIG. 6, the straight line L1 along the endedge on the face side of the raised portion 21 slopes relative to thetarget line rather than being orthogonal thereto, whereas the straightline L2 along the end edge on the back side of the raised portion 21extends so as to be generally orthogonal to the target line. Thus, ataddress, the orientation of the end edge on the back side of the raisedportion 21, rather than the upper end edge of the face surface, can bealigned with the target. Accordingly, the golfer is able to address theball without feeling any sense of incongruity, even with the facesurface in a closed state.

(3) Also, when the above in equations (2) to (6) are satisfied inaddition to the above in equation (1), the golfer is better able toaddress the ball without feeling any sense of incongruity, even with theface surface in a closed state.

(4) Also, when the above in equation (7) is satisfied, the face issquare (orthogonal to the target line) or the face is open (e.g., faceis turned to the right of the target direction, in the case of aright-handed club), in the reference state. Thus, when the club isgripped at address with the head in the reference state, the end edge onthe back side of the raised portion 21 extends in a direction that isopen to the target direction (e.g., in a direction whereby the directionorthogonal to the end edge on the back side of the raised portion 21 isturned to the right of the target direction, in the case of aright-handed club). Golfers tend to feel a sense of incongruity in thecase where the point of reference at address is turned in a directionthat is closed relative to the target direction. Therefore, this senseof incongruity can be eliminated by satisfying the above in equation(7).

7. Variations

Although an embodiment of the present invention is described above, thepresent invention is not particularly limited to the above embodiment,and various modifications can be made without departing from the spiritof the invention. Also, the following variations can be appropriatelycombined. Modifications such as the following can be made, for example.

<7-1>

In order to obtain the abovementioned effects, the raised portion 21need only be formed such that at least in equation (1) is satisfied.Accordingly, in equations (2) to (7) need only be appropriately set ifneeded.

In the above embodiment, the raised portion 21 is formed to be U-shapedin plan view, but is not particularly limited thereto. That is, as longas in equation (1) is satisfied, an end edge 211 on the back side of theraised portion 21 can, for example, be formed linearly, as shown in FIG.7A, can be formed to bend at one or a plurality of places between theposition Pt and the position Ph, as shown in FIG. 7B, or can be formedto curve, as shown in FIG. 7C.

<7-2>

In the above embodiment, the sloped surface 23 is formed to be U-shapedin plan view, but is not limited thereto, and need only extend generallyin the toe-heel direction. Accordingly, the sloped surface 23 can alsobe formed in a band shape extending generally straight in the toe-heeldirection, for example. Also, the sloped surface 23 may not necessarilybe flat. For example, the sloped surface can also be formed to becurved. Furthermore, the region between the raised portion 21 and thebase portion 22 need not necessarily be formed as a slope, and may be astep that extends in the up-down direction.

<7-3>

The head according to the above embodiment is constituted by combining ahead main body having at least the crown portion 2 with other portions,but the present invention can also be applied to a head in which onlythe crown portion 2 is formed separately. For example, the head can beconstituted by fitting the crown portion 2 into an opening for the crownportion formed in a head main body that includes a face portion, a sideportion and a sole portion. Also, a cup face structure need not beadopted, and the head can be constituted by fitting a plate-like facemember into an opening formed in the face portion 1 and welding the facemember to the head main body.

Working Examples

Hereinafter, working examples of the present invention will bedescribed. The present invention is, however, not limited to thefollowing working examples.

Here, golf club heads having generally the same shape as FIGS. 1 to 4were produced as working examples 1 and 2 satisfying the above inequation (1), as described above, and as comparative examples 1 and 2not satisfying the above in equation (1).

Working example 1 Dt/Dh = 1.2 (Dt = 22.0 mm, Dh = 18.3 mm) Workingexample 2 Dt/Dh = 1.3 (Dt = 23.8 mm, Dh = 18.3 mm) Comparative example 1Dt/Dh = 1 (Dt = 18.3 mm, Dh = 18.3 mm) Comparative example 2 Dt/Dh = 1.4(Dt = 25.7 mm, Dh = 18.3 mm)

Twenty golfers tested the golf clubs produced as described above. Thatis, sensory analysis was conducted in fine weather conditions as towhether any sense of incongruity was felt when the face surface wasclosed at address. As a result, with working examples 1 and 2, all ofthe golfers responded that they did not feel any sense of incongruity ataddress.

On the other hand, with the comparative example 1, 60 percent of thegolfers responded that they felt a sense of incongruity at address. Withthe comparative example 1, the end edge on the face side and the endedge on the back side of the raised portion were parallel to each other,and thus the sense of incongruity was apparently due to the fact thatnot only the end edge on the face side of the raised portion but alsothe end edge on the back side was not orthogonal to the target line (thetoe side was angled to the face side), when the face surface was closedat address.

Also, with the comparative example 2, 25 percent of the golfersresponded that they felt a sense of incongruity at address. With thecomparative example 2, the width of the raised portion on the toe sidewas much greater than on the heel side, and thus the angle formed by theend edge on the face side of the raised portion and the end edge on theback side was apparently felt to be excessively large. Thus, a sense ofincongruity was apparently felt due to the fact that the end edge on theback side of the raised portion was not orthogonal to the target line(the toe side was angled steeply to the back side), when the facesurface was closed at address.

LIST OF REFERENCE NUMERALS

-   -   1 Face portion    -   2 Crown portion    -   21 Raised portion (first region)    -   22 Base portion (second region)    -   23 Sloped surface (step region)    -   3 Sole portion    -   4 Hosel portion

What is claimed is:
 1. A golf club head comprising: a face portion; acrown portion; and a sole portion, wherein the crown portion includes: afirst region extending in a toe-heel direction along at least part ofthe face portion; a second region arranged further on a back side thanthe first region; and a step region extending in the toe-heel directionbetween the first region and the second region, and extending downwardtoward the second region from the first region side, the first region isformed to at least extend from a position Ph that is 20 mm on a heelside to a position Pt that is 25 mm on a toe side, based on a facecenter, and a width Dh of the first region in a face-back direction atthe position Ph and a width Dt of the first region in the face-backdirection at the position Pt satisfy 1<(Dt/Dh)≤1.35.
 2. The golf clubhead according to claim 1, wherein (Dt/Dh) is 1.3 or less.
 3. The golfclub head according to claim 1, wherein (Dt/Dh) is 1.25 or less.
 4. Thegolf club head according to claim 1, wherein (Dt/Dh) is 1.05 or more. 5.The golf club head according to claim 1, wherein (Dt/Dh) is 1.1 or more.6. The golf club head according to claim 1, wherein a difference betweenthe width Dh and the width Dt is 6 mm or less.
 7. The golf club headaccording to claim 1, wherein a length of the first region in theface-back direction is 5 to 30 mm, between the position Ph and theposition Pt.
 8. The golf club head according to claim 1, wherein Dt is10 to 30 mm.
 9. The golf club head according to claim 1, wherein Dh is6.5 to 30 mm.
 10. The golf club head according to claim 1, wherein anangle θ formed by a straight line connecting the position Ph and theposition Pt at an end edge on a face side of the first region and astraight line connecting the position Ph and the position Pt at the endedge on a back side of the first region satisfies 0 degrees<θ≤8 degrees.11. The golf club head according to claim 1, wherein a face angle FA ofthe face portion satisfies −5 degrees≤FA≤0 degrees.
 12. The golf clubhead according to claim 1, wherein the step region is formed to besubstantially U-shaped in plan view.
 13. The golf club head according toclaim 1, wherein the end edge on a back side of the first region betweenthe position Ph and the position Pt is formed linearly.
 14. The golfclub head according to claim 1, wherein the end edge on a back side ofthe first region between the position Ph and the position Pt is formedto curve.
 15. The golf club head according to claim 1, wherein the endedge on a back side of the first region between the position Ph and theposition Pt is formed to bend at least one place.